Selective electrical signaling.



L. M. POTTS.

' SELECTIVE ELECTRICAL SGNALPJGA APPLICATION FILED ram/7,1910. nEnEwEU APR. :3, ma.

MMM/meow L. M. POT-TS.

SELECTIVE ELECTRICAL SIGNALING. APFUCATIGN FILED MAY?. 1910. RENEWED APR. 13,1912.

l gli in Patented Apr. 13, 1915` www@ 1 i 111. mi ,W1 www' ,y www L. M. PUTTS.

` SELECTIVE ELECTRICAL SIGNALING. APPLICATIQN man MAY?, i910; RENEWED APR. 13,1912.

L M. PUTLS.

'-ILEUTIVE ELECTRICAL SIGNALING.

4 uw M l ,MW LTT iwf 5 SHEETSSHEET 6.

Il e H u v i i L l I RENEWED APR.13.1912.

I I [il w IV l' I Ji 1 L i "V 6 i@ e f 9|@ L L i l LOUIS MAXXVELL PGLTS, Olli? BALTMRE, MARYLAND, ASSIGNOR, BY MESNE ASSG'N- MENTS, EIO AUSTIN MCLANAHAN, F BALTIMRE, MARYLAND. I

SELEC'VE ELECTRICAL SIGNALN Ct.

i ,lascar Specification of Letters Patent.

Patented Alpi. 13, lhlilii.

Application ledll/Iay 7, 1910, Serial No. 559,967. Renewed April 13, 1912. Serial No. 690,659.

To all whom 'it may concern Be it known that I, Louis MAXWELL Porra, a citizen of the United States, residing :xt Baltimore, in the State of Maryland, have invented certain new and useful Improvements in Selective ElectricalSignaling, of which the following is a specilication.

This invention relates to selective 'electrical signaling which, broadly considered, includes the operation of electric telegraphs,

telephones or* any other apparatus where it is desired toEe'ect a. series of mechanical operations by electrical signals sent over a line', and the primary object of the said invention is to provide afsystem of this character which .shall he positive and accurate in action. and at the same time comparatively simple.

The transmitting apparatus herein shown and described forms the subject of a divisional application hereof filed. May 20, 1913,

Sein No. 768,773.

ln order that my said invention .may be more fully understood., l shall now describe in detail, with reference to the accompanying drawings, one specific embodiment thereof, and later point out what I claim.

ln the accompanying drawings, Figure 1, is a diagram of an arrangement of receiving circuits and apparatus embodying my said invention; Fig. 2, a side elevation and diagram of 4circuits of a form of the transmitting apparatus above referred to. Fig. 3,is a section on line ith-SX Fig. 2 looking upward, with many parts omitted. Fig. 4, a

fragmentary detail plan view partly 'in` 4section to show the position of one of the cams of Fig. 2, relative to its operated lever when the apparatus is at rest; Fig. 5, is a section on line *5x- 5* Fig. 2, with many parts omitted; Fig. (l, is a top plan view of the transmitting apparatus Fig. 2, ywith many parts omitted; Fig. 7. a fragmentary detail end elevation of the key locking mechanism shown in F ipfs. 2 and 3; Fig. S, a section on line SXT-8*. Fig. 2, with parts removed, and looking downward; Fig. 9, a section on line .9L-9X, Fig. 2, with parts removed. and looking;- downward; Fig. 10, a fragmeutm'y tup plan view of the slotted guide block and its levers; Fig. 1l, an enlarged -detail side elevation partly in sectien of the clutch mechanism of the trans? mitter of Fig. 2; Fig. 12, an enlarged detail perspective view of one of the clutch connecting pins; Fig. 13, a top plan view of one of the relays referred to in connection with Fig. 1; F ig. 14C, a diagram of combinations which may he used with my present system of signaling; Fig. 15, a diagrammatic View showing the arrangement of lugs on the selector bars shown in Figs. 5 and 6, and Fig. 16, is a diagram of the current on the line for a given signal embodying my invention.

ln the following description I shall take up first the reception of the signals, and for this purpose reference will now he had to Fig. 1, of the drawings. In the specific form of my invention shown in this figure, l employ two main line wires 1 and 2 which lead from a source of current at some sending station to the receiving station showin,

toward their back stop contacts by springs 6 and 7 The tongue of relay 3 moves between two contacts 8 and 9 connected to a split resistance 10 connected between the poles of a source of direct current, and this resistance is tapped at 11, s o that in a circuit leading from said point 11 to the tongue of the relay, -a current will pass in one direction when said tongue engages contact 8 and in the other when it engages contact 9. In this circuit from tongue of relay 3 to point 11 are permanently connected in series the forward coils of eight polar relays l2 to 19 inclusive. These relays have each two tongues Qo-er 24u25, as a'r,

.Q8-29, 3031. and 34.-35, respecformer with the restoring or hack coil as the primary, and'thus nullify the eeet of the restoring,- impulse. All or' the forward contacts of these relays are connected to a 5, common wire A36 which is tapped on to circuit fil, 8-9 at wire joint 3G. These contacts are normally open. All oi theghaclr contacts of these relays are connected to common wire 3'? which taps onto circuit 11, lo 89 at the tongue of relay 19. Thus we have a shunt around all the forward coils o said relays, said shunt comprising the two wires 36 and 37 across which are bridged pairs of contacts comprising respectively the la forward and back contacts of relay vtongues 20, 22, 24, 26, 28, 30, 32 and 3l. The tongues 20, 22, 24, 26, 28, 30, 32 and 34 of these relays are tapped on to circuit 11, 8-9 at points-between front coil of each relay and 2u that of the next following relay.

Relays 38 to 45 inclusive are the selecting relays, each of which has a single tongue and two tongue contacts. These may he polar relays of usual or any desired con- ;struction. These selecting relays are connectedto the relays l2-l9 as follows: The hack contacts of tongues 2l, 23; 25, 27, 29, Sl'and 33 of relays 12-19 are connected respectively in series with the forward coils to or relays 3ft-lei and thence all to a common return wire 46 which leads to negative of a source of local current supply as indicated. The forward coils ot' relay 45 however, connect to the forward contact of tongue 33 35 of relay i8. Ilhe forward-coil of this last mentioned relay also connects to common return- 4S. The tongue 21 of relay l2 is con nected direct to the forward contact of line relay il. The forward contact of" tongue 21 Fill connects to tongue 23 of the next relay l,

while the forward Contact of the tongue 23 connects to the tongue 25 of the next relay .14 and so on down to relay 18 which has the forward contact of itstongue 33 connected .45 to the forward coil of selecting relay 4.5.

The tongue 35 of relay 19 connects directly to positive of a source of local current, while its forward contact connects to negative of said source. The hack coils of all the re- 5@ 'lays 12-19 and 38%-45 are connected Ain series with avsource of local current, Ysaid .l circuit being normally open through the for ward contact and` tongue of line relay 5.

The tongues of both main line relays flea-ndy 5 are connected to positive of said source ol.

vlocal current. The selecting' relays 38-45 may he made to operate any desired receiving mechanism, such for example, as a printving telegraph receiver, or in fact any de 0 sired apparatus which may he operated hy the operation of local circuits in conoloiy nations. y

ln the diagram Fig. l, l have shown y indicating la form of receiving apparatus 5P' eight magnets 423-55 connected respectively to its forward stop. the local relays are all normally in the potions are well known in the art, and l. do not herein claim any of these niechunisn'is :is

part of this invention.

lf applied to a system wherein the sonders are synchronously driven, the selectingrelays 38--4-5 may, for example, he those of the Rowland system as described in ll. fd. Patent No. 718,497' granted November ll, 1902 or they may he the selecting relays ot the automatic telegraph forming the subject of S. Patent No. `9i-f2,8-lei, granted De cemher 7, 1909.011 an application filed by ine. These selecting relays may, however, he used to operate local circuits selectively for any desired purpose.

The magnet 56 represents any translating device to operate mechanism previously set by the magnets 4l855 as for example the printer spacing magnet of my application above referred to.

Normally, that is when no signals are on the line, continuous direct current is sent to line over hoth wircs'l. and 2. This current causes relay 3 to hold its tongue normally against contact 8. Local current then passes from positive of split resistance l0 tlirorghl wire 11, forward coil and tongue 20 oi" relay l2, wire 37, wire ll to point ll. current, however, does not lnove tongue 2() The other tongues o1 any,

Y.magnets energized selectively in comlnna- This.

sitions shown in the diagram. The conA tinuous current on line 2 during` this period of no signal on theline sends tongue ci rclay et against its hack stop and holds tongue of relay 5 against tension of spring ,7 in engagement with its forward contact. Each signal is made upo a series of impulses sent over line l to e'ect the setting ofthe pri mary relays 12e-49, and one or more selected impulses sent over line 2 to effect, in co1nhinatien with relays- MMM), the ope ation of the selecting relays 3S-45. 'l`hei1n1mlses onyline 1 may alternate in polarity, or he of any character whiclewill cause line relay 3 ,to `v1hrate itstongue between contacts 8, 9. Lilreiiise, the selective impulses on line 2 may. he of any vkind so longl the 'impulses which operate relay l will not operate re- Fig. 16 shows the current on the two lines 'for a xgiven signal, in which AMB represents the current ou line l, and C-D the current on line 2. ln the particular case shown in this diagram it is assumed that the nornntl current on line l is positive and that on line 'l0 Wire .'11, tongue and bach G circuit: rlongue of re lo ance with the system of combinations illustrated in the diagram ll 14. Referring to this ligure of the drawings, let the zig-zag row of dots through which passes the rer tical line cv-g/ represent respectively the i5 eight impulses a, b,- o, d, c, y, g and le. of

e. signal group on line 1.. These .dots then represent the eight code positions of a giren signal group. The'impulscs on line 2 for the respective signals occupy the code posi-- tions indicated by the dots under theyrespective transmittalole characters and other signals arranged in a` horizontal row along the top'of Fig. 14. For example, for the letter A two impulses would.v ce sent over line il occupying the t and l positions. The

signal actually shown in Fig. lo is the letter il for which the selecting@ impulses 4on line 2 occupy the I) and e positions.l The negative current at the end D of the line C-i-D, Fig. 16, restores the local relays 'to their initial positions, and further than this forms no part of theselective combination. *Each signal group .terminates in this way.

Let it loe assumed that the signal. for the letter H is received. Relay l in line 1 then receives the groupv of impulses f1-B, Fig. 16, and. the relays 4 and 5, the current las shown at Cul), Fig. 1G. The-first or c i' impulse on line 1 being positive, the relay 3 will continue to' hold its tongue against.

Contact 8. Relay i will also not at this time operate, for there is no current on line 1When,hofvever, current in line 1 reverses ,between the a and b impulses, the tongues ,2O and 21 of relay-12 go forward. Relay 12 is then' out. of circuit and relay 13 .is in circuit. This circuit 4which includes the for ward coil of relay 13 may be traced as fol lows: From point 11 of split resistance over contact of relay 19, Wire 37, baclccontact and tongue 2:2 of relay 13, forward coil of said relay 13, tongue 20 and forward Contact of relay 1'2, "Wire 11a and thence to the tongue of -line "5 relay The .tongue 20 of .relay 1S!y is nor.'

against its forward stop short circuiting its 'forward coil. At the saine time tongue of relay 2.- is against its forwardy stop.

-, Since now there is positive?) impuls-re on wire 2' corresponding to the negative f) impulse on Wire 1, the tongue of relay Llwill loe sent against its 'forward cor* Se looting relay 30 uill tlien receiw current through its forward coil over the feller."

lay L1, forward, contact of said relay, tongue 21 or relay '12, forward Contact of said relay, tongue 23 of relay 1 3, back stopof said relay, thence throughv 'for ward coil of relay 39 to negative. This will stoos andin doinfy so each of said relays cuts itself out of circuit, th at is, its forward coil, and, cuts the next succeeding relayinto circuit. The relays previously cut out in a similar Way remain cut out until the general restoring impulse comes along. rTherefore when the c iinpul se on line 2 is received, the rerersal takin-g place between the d and c impulses, line has caused relay l-i to send its tongucs and 2T against their forward contacts and the c impulse on lineV 2 has sent the tongue of relay -l against its forward stop.y thus completing a circuit from the tongue of that relay through tongue 21-and its forward contact, tongue 23 and its forward contact, tongue 25 and its forward contact, tongue 9.7 and its forward Contact, tongue 2) and Aits'bacli; stop, through forward coil of relay #l2 to nega-V tive thus caiising relay 452 to operate transI- lating device At the end of the signal the normal current again passes negative to line This current will not atleet relay E s relay so wound that current Athis direction siini'ily tends to hold its tongue against its haclistop. .Relay honw over, is so Y'wound that this nega 'ire current sends its tongue against its forward contact, where it romains until the next signal is received. When the tongue of this relay 5 does engage its forward contact it co1n- -pletes a circuit which may be traced from the positiw. terminal of source of local current, tongue of relay 5, its forward contact, wire fthrougli the hacl; coils of all the relays 19.-19 and fil-3S tonegutive. -Currcnt in "shis circuit restores all the y`tor ..ues of said relays to their haclrstops and. this places them in cordition to rcceire a nea.v signal. ln a inilar nay any of the signals iu the :liagruin Fig. 1-1 may he re ceircd.l The nerds Space, Line, lac.lr,and lanlc indicate signals used in. transn which forms the subject' of a separate application. f

pointed out in the general introduction .o this spec ation, the transmitting ap- ,aratus hereln shown and described foi-ins ,he sulijr-xct of a divisional applicati on. liet rence therefore must be had to said diriincassi transmission and reception, and also claims whichinclude transmitting apparatus 'as a part of thel combination. It is therefore proper that said` transmitting apparatus should he described in the present specitication also. |his transmitting apparatus comprises, among other parts (seeFigs. 2 to 18, inclusive).A asuitable support in the forinof a plateJ 58, provided withbearings 59, .601m which is journaled a shaft 61 which is adapted to be connected with any suitable source of driving power. In the drawing l have shown this shaft driven from a small electric motor 62 geared to it through worm gearing 68.

The shaft 61 carries among other things a sleeve 64 loose thereon. Mounted fast on this sleeve, in addition to other parts, are two cams 65 and 66. Cam 65 has four similar projections 67 and anv elongated intervening space 68 (see Fig. 8), and cam 66 has three projections 69, similar to 67, and

one elongated projection 70 three'times as long as projections 67 and 69. These cams Y are so arranged on sleeve 64 that elongated projection 70 lies opposite elongated space 68, so that the two 'cams together divide a circle into lseven equally spaced projections 67, 69 and one projection 70 three times as. long. The object of this spacing will be apparent later. Thesecarns 65 and 66 engage respectively two pivoted levers 71 and 72' which carry respectively insulating studs 73 and 74, which in turnrengage two Contact springs 75 and 76 secured to an insulating hase 77, and movable respectively by said levers into engagement with contact screws 78 and 9 in metal bridge 80 secured to in- I sulating. base 77. Also mounted on sleeve 6l are eight cam disks 81 separated by spac ing disks 82 all of which are secured rigidly togetherand to a cani 88, so that they form a sleeve. This cani sleeve is slidable longitudinally on sleeve 64:, but is made to yrotate therewith by eather engaging an elongated slot 84 in sleeve 64. (#See Fig. 11). Each disk 81 carries a cam lug 85 and these llugs are spaced spii'ally around the sleeve formed by disks 81-82. Each of said lugs extends over approximately one tenth of the circumference of said sleeve, as shown most clearly'inFig. 9. rhese cam lugs 85 Aare adapted at times to engage each an I' end. of 'one of a vseries of eight levers 86,

all mounted on regl 87 as a common ulcrum, the said red being supported at its ends in4 bearings 88, one only of which is shown. (See Fig. 9). The heads or upper ends of these levers 86 worlr in individual slots in a block 89 on the base plate 58, thereby holding the upper ends of said levers against the lateral thrust'tc which, they are subjected in the operation of the device. The head of each lever 86 is provided with a cam .lip 90. The lower end of each ol these levers is provided with a short arm 91 to each of which is attached an individual coilspring 92, the other end Aol' which springs are secured to a bracket 98 made fast on the base plate 58. The springs normally" hold the upper ends of levers 86 out of the path of cam lugs 85. (See Fig. 9). The insulating base 77 is hollowed out for a portion of its length to receive the lower end of levers 86 and their associated parts.

" Cam 83 is adapted to engage a conical cam roller 94 mounted on one end of a pivoted lever 95 which carries at its other end an insulating stud 96 'adapted to engage a con-- tact spring 97 to bring the same into engagement with a contact screw 98011 a metal bridge 99. i

The sleeve made up of disks 81--82 is normally forced under tension of aspiring 100 up against a collar 101 fast on sleeve 64, so that normally cam 83 does not operate on roller 94. Spring 100 is `held between cam 83 and the collar of a cam 102 also fast on sleeve 64. This last mentioned cam engages one end of a bell-crank. lever 108 one of the arms of which carries a stud 10i adapted to operate a Contact spring to bring the same into engagement with a contact screw 106 on the bridge 99; while another arm of said lever actuates certain keyloclring mechanism hereinafter described. The sleeve 64 receives its motion :trom shaft- 61 through a clutch 107, which consists among other parts of a normally rotating member 108 made fast on shaft 61,l and a normally stationary member 109 fast on sleeve 64. For the details of this clutch, see Figs., 11 and 12. v

he clutch member 108 is provided with annular flange 110 on which are cut radial teeth 111; The member 109 has two annular flanges 112 and 113 in which are mounted for movement transversely thereto a cani latch llhaving teeth 115 at one end adapted to engage the teeth 111, and cut away as at 116 to receive the nose of a lever hereinafterdescribed. One of the walls of the recess 116 forms a cam 117 adapted by engaging said nose to shift said latch. 118 fast on member 109 presses against the end of latch 114 to force it toward. member ed to a contact spring 123 secured at one A. spring end to base 77. This spring 123 is adapted to normally engage a contact screw on metal bridge 125, but is adapted to hrealr slide longitudinally of the shaft. The loose forming a part'of member 130 of clutch- 131. The member of this clutch including collar 129 and cam 128v are all loose on'shaft 61, that is, this shaft may rotate relative to said parts but the latter cannot member 130 of clutch 131 carries a coupling pin 132 (see Fig. 11) which is a duplicate of pin 114 of clutch 107, and this pin (132)- is adapted,'as in the iirst described clutch, to engage teeth 133 '015 the member 134: fast on shaft 61, underth'efaction ot spring 135. rThe coupling and uncouplingvof the fast and loose members of clutch`131 is controlled by a .pin 136 which engages e'am recess 137 in coupling pin 132, and this pin (13G) isI carried by one end of a lever 13S made fast on a rock-shaft 139 journaled in bearings 140, 141. Also mounted fast on shaft 139 is a lever rests'on the periphery of a cam 143 made fast to the loose member 109 of clutch 107.

This lever 112 is held against cam 143 under tension of a spring 1411, attached to an arm 111-5 on shaft 139 and "to the base plate 53.

The signals are 'formed in this apparatus by operating the levers 86 so as to bring combinations oi' said levers into the paths of the cam lugs S5. For this purpose I employ eight slidable pins 146 which are preferably arranged in two rows o'f four each and staggered as shown. The. operation of? these pins'may be effected eithery automatically or manually. lln the embodiment of my invention herein shown this operation is effected manuallyby means of a" keyboard and associated mechanism. rlhis mechanism comprises in the present case eight selector bars 1117, one for each of said pins, mounted side by side for lateral movement. The movement of these selector bars, in the case shown, is effected by means oi pivoted keys 113 having cam edges 149 adapted to engage cam lugs 150 ortthe selector bars. By arrangingthese lugs on said bars so as to be engaged in certain coinbinations by the several keys, the said bars are caused to operate said pins in these combinations. The manner of arranging these lugs onthe selecting bars will be clear from Aa study of Fig. 15 which shows in side elevation four oit' the bars removed from the machine. These lugs are simply arranged so that v4there will be the reipiired number in'liiiewitheacn key lever to shi'lt that one or combination of bars which corresponds the .character or other signal which the .iciil'ar key lever represents. For examletter A is formed bythe a. and l 142 one end of whichl combinations or code positions. Therefore, the a and Z bars 14:7 would each have a lug adapted to be engaged by the beveled edge of the A key lever, so that when the A key is operated the said a and d bars will be shifted.

4Each selector bar is provided on its upper edge with a lug 151 any one oiI which is adapted, when its bar is operated,'to engage the yoke of a lever 153 which operates a slidable pin-1511 adapted to operate a contact spring 155 made astat one end to. insulation support 77 and in line with a contact screw 156 onbridge 125. Pin 154 carries at one end an insulating tip 157 which engages spring 155.

The keys of the keyboard, which may be .of any desired number, are preferably held locked against operation during the cycle o' sending each signal. This is eected in the present case by providing each key with a lip 158 which is adapted to be held against movement at times by a locking bar 159 tending across all the keys and mounted at its ends on pivoted uprights 160. This locking bar is rocked so as to lock and unlock the keys by means et ,lever 103, one of the arms 161 of which is connected to upright through link 162 pivoted to the upright 160 as at 163 (see Figs. 3, 5 and 7).

The signaling current is olied in the ease 'shown by two direct current dynamos 164 and 165, a vpositive terminal or' one and a negative terminal of the other of said dynamos being connected together and to earth shown; Positive terminal of dynamo 1641, isA connected through resistanccs 166 and 161' to contact springs 76 and 97 respectively, while the 4negative terminal of dynamo 165 is electrically connected through resistances 168 and 169 to contact springs 75 and 105 respectively. Line 1 connects to bind .lg

'post 170, on metal bridge 80, and line 2 connects to binding post 171 on metal bridge 99. Une terminal of a local source of current is connected to one of the terminals of magnet 122 while the other terminal of said source is connectedto the bindinglpost of spring Contact 155. l

The operation of the foregoing trai'ismitting apparatus is as follows: Shaft 61 rotates continuously. Consider irst the norinal ycondition oi the line when no signals are being transmitted: During this time line 1. receives positive current continuously from dynamo 104: through contact spring 76, con tact 79- and binding post 170. When the apparatus is at rest cams 65 and 6G always stop in such position that lever 72 rests on the elongated projection 70 so as to ,hold spring 7G into engagement with contact 79. (See, Fig. 8.) .Line during this time receives continuous negative current from dynamo through Contact spring 105, contact 100 and binding post 171. Cam 102 always stops izo GRU

.till

on said line, and means to restore all of said relays to normal after each signal,

10. lu. a selective signaling system, the combination Vwith fa signaling circuit, of ineens to send a.' plurality of electrical impulses over said circuit, a plurality of relays the forward coils ot' which are connected in series in said circuit, each of said relays ha ing a plurality of sets of stationary forward and bacli contacts and a movable tongue contact for each of said sets, atWo wire shunt tapped on to Jsaidlocal circuit around the forward coils 'of all oi. saidrelays, one set of 'forward and'bamceontacts of each of said relays being connected in multiple formation beti'yeen the twofjwires of said shunt, and the respective"niying contacts of said sets in said shunt Abeingtapped on to said Vsignaling circuit at points intermediate of the successive forward coils of said relays.

llQ ln a. selective signaling system, the combination with 4signaling circuit, of ineens te send a' plurality of electrical imiiiulses' over seid circuit, aplurality of relays forward coils of which are con necteo. series in said circuit, cach of said relays lievi' a plurality of sets el: stationforufard haelt contacts and a moy contact for each of said sets, a two wire shunt tapi'ied on. to, said local circuit around the forxjvard coilsw'of all of said relays, one set of forward and back contacts .oit cachot said.v relays being connected in multiple formation betweenthe two wires of said shunt., `and the respective moving con tacite of said, sets in said shunt beingtapped on to said signaling circuit at points interliate o relays, a'second signali-nc,P circuit, means to impress selected electrical impulses on said circuit, and receivingapparatuses contro-lied by' said `impulses in combination with contacts opera-ted by said relays.

lf2.. 'in a selective signaling system,- the combination with line signaling circuit, ot' a relay included inv and operated by current inlcad circuit, alocal circuiuiueans whereby 'the Vibration of the tongue of said liuc relay between its contacts sends a Aplurality electrical impulsos over said local circuit, a plurality of local relays the `forward coils vwhich are connected in series irf said local circuits, each. of said relays having a plurality of sots of stationary forward and back contactsand a movable tongue contact for each ff said sets, a two wire shunt tapped .on 'to said local circuit around the. forward coils ci all of said relays, one sot of forward and back contacts of cach ot said relays being; connected in multiple "formation besaid si 'icing tapped on to said local circuit ai .nnte intermediate of the successive the successive forward coils of incassi.

'forward coils of said local relays, and means to impress a series oi' electrical impulses on the said line whereby said line relay is caused to vibrate its tongue.

13.331 a selective signaling system, the combination with a line signaling circuit, of a relay included in and operated by current in said circuit, a local circuit, means where by the vibration of the tongue of said line relay between its contacts sends analteruat ing current over said local circuit, a plural.- ity of local relays the forward coils of which are connected in series in said local circuit, each of said relays having a. plurality of sets of stationary forward aud hack contacts and a ,movable tongue contact for each ci" said sets, a shunt tapped on to said local cir cuit around the forward coils oi all of said relays, one set of forward and back contacts of each of said relays being connected iu multiple formation in said shunt, and the respective vmoving' contacts of said sets in said shunt being 'tapped on to said local ci rcuit at points intermediate of the successi vc forward coils of said local relays` means lo impress a series of electrical impulses on the said line whereby said line relay is caused to vibrate its tongue, a secondl liuc signaling; circuit, a liuc re connected. iu and oper ated by current in id second line circuit, u local ycircuit including a, plurality of brauch circuits, the tongue und. forward contact ol" said line relay being common to all of said branch circuits, and each branch .circuit being individually controlled by the iii-st named local relays, a selecting,u relay counected in and operated by each of said branch circuits, and means to impress :5c-- lected electrical impulses on said second line to operate said selecting,- relays.

lfi. A selective signaling system comprising, in combination, a plurality of electroi magnets connected in series, a variable shunt cmnprisinga terminal connected to the bcginningot said series connection and a terniinal connected to the cud. of Said series connection, and taps iuteruied'atc of said serios of elcctroinagncts movable to conneet with either o'lE said terminals.

A selective signaling system coiupris-- ingr iu combination a plurality of relays con nccted in` scrizes, a variable shunt compusiu'cj u terminal connected to the beginning ot said series connection and :i terminal conh uccted to the end oit said series connection, the tongues olithe respective relays beingtapped on to said series connection at points inl .inxe. li:|i'o oil the respective relays.

16. A selective signaling system comprisinni, in combination, :L plurality ol' Sets of electrical contacts, conductors individual to euch oli said sets and movable to coupure either contact of the respectivo sets, one cou-- tact of each. connected to :i movable con.vv

Gli

o' il ilu l. ll

rex

oluctcr ci another set, ancl a plurality' ct' electro-ma. ets connected respectively in circuit Witihnthe remaining contact of each. of said sets. Y,

1'?. A selective signaling system comprise',

ving, in combination, two series of relays in signal, causing these two separate sets of impulses to conjointly. operate receimningP apparatus, and. at the enel o'each signal transn mitting over the linea restoring current ditn tering in. character from either o' the signaling currents, for the purpose of restoring the receiving' apparatusto its normal conflition tc receive a fresh signal.

1 9. A selective electrical signaling system cmnprising two line circuits, stepfhyetep suitchingmeans operated by current in one of sairl circuits, sii/itching means operated by current in the other of said circuits, and a series ot circuits controlled hy the conjoint action of saicl step-bystep apparatus and the second mentioned switching means, the sairl step-hy-step switching means being at rest except on the transmission of signals.

20. A. selective electrical signaling system comprising; two line circuits, step-hy-step hingv means operaterl hy current in one ci sairl circuits, switchingn means operated by curi nt in the other of said circuits, the two devices acting conjointly to control one or incre circuits.

i selcctiye electrical signaling system comprising two line circuits, a series of switches oiicratccl in step-hy-step order hy current in one of saidcircuits only, a switching lei/ice responsive to current in the other of said circuits only, and a, series oit circuits controlleci hy the conjoint action ci? said the tongue of said line relay with its contacts operates said series of relays in stephyestep order, a series of switches operateclv hy said relays in step-hy-step order, a line reley responsive to the selected signaling limpulses of the second named line circuit,

anol a series of circuits adapted to be controlled by the conjoint action of said series of switches and said last named line relay.

The method of electrical signaling, which consists in impressing on a circuit a group of similar electrical impulses on each signal transmission for synchronizing, and simultaneously impressing on a separate circuitl one or more selected electrical impulses clilering for each signal, and causing Athese two separate sets of impulses to conjointly operate the receiving' apparatus, the synchronizing impulses being impressed on the line only on the transmission of signals.

2st. Vlhe method of electrical signaling which consists in impressing on an electric .circuit impulses -for synchronizing, and impressing on a different circuit selected impulses for signaling, and causing these two separate of impulses to conjointly operate electrical translating apparatus, the synchronizing impulses being impressed on the line only on the transmission of signals.

ln testimony whereof I aliix my signature in presence of two witnesses.

' LOlUlS MAXWELL PGTTS.

lliitnesses lnancis S. MAGUIRE, onu H. Hour. 

